The present invention relates to a computer program storage medium suitable for treating data obtained from an synchronized electrocardiogram tomoscintigraphy, as well as a method and an apparatus for executing in a computing system the treatment of said data.
Reference is made to various publications for disclosing specific analysis or techniques used in the program and method of the invention.
These publications are:
xe2x80x9cIschemic heart disease and regional left ventricular wall motion: a study comparing radial, centerline and a video intensity based slope techniquexe2x80x9d, International Journal of Cardiac Imaging 6:85-96, 1990/91, Sunnerhagen et al;
xe2x80x9ceffect of myocardial wall thickness on Spect quantificationxe2x80x9d, IEEE Transactions on Medicakl imaging, vol 9, No 2, June 1990, pages 144 to 150, James Galt ety al;
xe2x80x9can efficient uniform cost algorithm applied to distance transformsxe2x80x9d, Verwer et al, IEEE transactions on pattern analysis and machine intelligence, vol 11, No 4, April 1989, description of distance transform;
xe2x80x9cWatersheds in Digital spaces: an efficient algorithm based on immersion simulationsxe2x80x9d, Vincent et al, IEEE transactions on pattern analysis and machine intelligence, vol 13, No 6, June 1991, (description of the watershed);
xe2x80x9cTowards automated analysis in 3D cardiac MR imagingxe2x80x9d, Bister et al, lecture notes in Computer Science, Springer-Verlag 1991, IMPI 91, 12th International Conference on Information Medical imaging, Wye, UK, pp 205-217 (description of the PDM and the egmentation);
xe2x80x9cDigital Image Processingxe2x80x9d, Gonzales et al, Addison-Wesley Publishing Company, 1992, page 81 to 92 and pages 119 to 128, (the FFT method);
xe2x80x9cDigital Picture Processingxe2x80x9d, Rosenfeld et al, Academic Press, 1982, pages 42-46 (the matched filter);
xe2x80x9cuse of watersheds in contour detectionxe2x80x9d, Beucher et al, International Workshop on Image processing, real time edge and motion detection/estimation, Rennes, France, September 1979;
xe2x80x9cDistance transformations in digital imagesxe2x80x9d, Borgefors, Journal CVGIP(34), No 3, June 1986, pages 244-371 (description of distance transform).
The content of these publications is incorporated in the present specification by reference for the disclosure of specific methods, algorithms, etc.
The majority of the cardiac pathologies cause an abnormal function or working of one or more cavities of the heart, and/or an abnormal volume for these cavities. For example, a lack of heart perfusion could lead to ischemia and/or infarct: these muscular fiber lesions don""t allow a correct contraction of a portion of the heart. Also, pericardium problems, (for example a hardening or thickening of the heart envelope) will cause an abnormal expansion of one or more cavities. An abnormal working of the heart valves will modify the normal transit of the blood into the cavities, reducing the blood output. So, severe abnormal working or volume of one or more cavities of the heart will cause major problem in the blood flow and thus in the vascularisation of the body. These pathologies can also be associated with severe troubles in the cardiac rhythm, conducting to sudden deaths by stop or anarchic contraction of the cardiac walls.
Therefore, there is a need for having a correct analysis or view of one or more cavities of the heart.
Cardiac scintigraphy synchronized with ECG is a known technique for studying the heart. Before the acquisition really starts, the mean duration of a cardiac cycle is calculated and time interval are defined (the xe2x80x9ctime binsxe2x80x9d) . By said technique, it is possible to visualize, by means of gamma rays, the distribution and the concentration of a radioisotope present in the heart during the cardiac cycle. There are roughly two approaches: the analysis of the myocardium and the analysis of the cavities themselves. There are also 2 major techniques: the planar and the tomographic scintigraphies:
a) the analysis of the myocardium: using an perfusion myocardial tracer (a product staying in the myocardial cell proportionally to the local flow and labeled with an radioactive agent) allows a good visualization of lack of vascularisation into the walls of mainly the left ventricle (LV). The topography technique allows a visualization in 3 dimensions (3D) of the heart, which is not possible with the planar (1 or 2 incidences) technique. This analysis has the drawback that the variation of maximal activity in the wall, which is correlated to the thickening of said wall, is influenced by a partial volume effect (Galt, 1990), and therefore based on a data which is not only correlated to the number of registered photons, but also to due to a lack of resolution. Moreover, the maximum variation is also correlated to the attenuation of the rays between the emitting heart portion and the detecting means, said attenuation of the rays being variable from patient to patient and, for the same patient, from place to place inside the thorax.
Furthermore, this analysis does not give a correct and precise view of the basal portion of the left ventricle, nor in the right ventricle and in the pathologies relating to local perfusion. Therefore, the analysis given many uncertainties about the exact shape and volume of said ventricles. Walls of the auricles or portion thereof arc also not visible.
Furthermore, the known myocardial scintigraphy technology is not adapted for correcting the image due to the movement of the heart. These movements could be due to motion of the heart in the thorax and/or due to the movement of the thorax (caused for example by the breath) and/or due to a movement of the patient during his examination. There is no place defined by the said technology in the heart, which can be used as a reference: a correction of the general cardiac motion is not possible.
b) the analysis of the cavities themselves: it has been proposed to study directly the heart cavities by labeling the red blood cells by means of a radioactive element, such as a gamma emitter or a positron emitter. This method gives only a substantially correct view of the inner wall of the heart, but give a goof imaging of all the cavities of the heart. The major problem of the planar imaging technology is that there is an overlapping, in the different views, of the cavities, whereby the limits and, a fortiori, the wall motions and the volume of one cavity are difficult to appreciate and to quantify.
In the known apparatus the data are treated so as to give a 2-dimension or 3-dimensions (time +2 spatial dimensions) analysis. In the treatment of the data, the cardiac activity is not really corrected in function of the position of the heart or a portion thereof: the proposed 2D correction use the centroid of the (ventricular) cavity as the reference point for the evaluation of the segmental wall motion, but this centroid can be falsely displaced during the cycle if the wall contraction is not synchronous and/or symmetrical (which is even physiologically generally not the case).
It has finally also been proposed to make a tomographic analysis of the heart, said analysis studying the different volumes in function of the time. Said analysis gives many data""s to the operator or user, said data""s being as such quite complicated to be analyzed. The analysis gives a series of images, each image being defined by a matrix, classically of 64xc3x9764xc3x9764 pixels and 8 time bins, each time bin corresponding to a part of the heart cycle.
The present invention aims, in a tomographic analysis of the cardiac chambers synchronized with ECG, to normalize the cardiac time bin activity, to correct for the global motion of the heart inside the considered matrix, to label the different cardiac cavities, to extract from these data the meaningful parameters and to display them in a 2D way appropriated, when necessary, to compare with normal data bases, so as to enable in preferred embodiments, at least a automated preprocessing of a four or five -dimensional analysis of one or more chambers of the heart, which could be afterwards easily controlled and corrected by the user.
In this document, the word  less than  less than pixel greater than  greater than  is used irrespective of the number of dimensions involved (2D,3D,4D,5D, . . . ) The present invention relates to a computer program storage medium readable by a computing system which is useful for the analysis of the function of at least one cavity of the heart, especially for the analysis of the function of the fourth cavities of the heart, namely the left auricle, the left ventricle, the right auricle and the right ventricle.
According to a specific embodiment, the computer program can receive one or more inputs from the user for correcting the image received from the tomoscintigraphy apparatus, said image being obtained by the detection of positrons or photons.
A correct tomography analysis allows a visualization of one or more cavities of the heart, preferably of all the cavities of the heart, without superposition of the views.
A first object of the invention is a computer program storage medium readable by a computing system and encoding a computer program of instructions for executing a computer process for the treatment of data obtained from synchronized electrocardiogram tomoscintigraphy, said data being correlated to image giving the activity of a heart comprising auricles, ventricles, valves and septum, said image comprising at least: (a) a first portion consisting of the pixels showing the auricles and ventricles during the cardiac cycle, each cycle comprising successive time bins with an end-systole time and end-diastole time, and (b) a second portion consisting of pixels substantially not involved with said cardiac activity, said computer process comprising at least the steps of:
reading data obtained from the synchronized electrocardiogram tomoscintigraphy corresponding to 3dimensional images at different time bins, said images being defined by pixels;
normalizing the activity at each time bin;
determining a rigid model comprising a reference;
determining, for each time bin, the correction movement for matching the reference and correcting fot this in each time bin;
determining the time bins for end-systole and end-diastole;
determining the phase and amplitude of pixels of the 3dimensional images;
filtering temporally and spatially
substracting the background
segmenting the images;
temporal and spatial filtering;
labeling the ventricles and the auricles
computing at least a parameter selected from the group consisting of activity curves, thickness of at least a portion of the septum, ventricular movements;
determining of 2D representations ofsegmenrtal motion, and
a displaying results.
Advantageously, the data read are 3dimentional images at different time bins for at least two different physical states (for example at different efforts, before and after absorption of a drug, etc.).
A second object of the invention is a computer program storage medium readable by a computing system and encoding a computer program of instructions for executing a computer process for the treatment of data obtained from synchronized electrocardiogram tomography, especially electrocardiogram tomoscintigraphy, said data being correlated to image giving the activity of a heart comprising auricles, ventricles, valves and septum, said image comprising at least: (a) a first portion consisting of the pixels showing the auricles and ventricles during the cardiac cycle, each cycle comprising successive time bins with an end-systole time and end-diastole time, and (b) a second portion consisting of pixels substantially not involved with said cardiac activity, said computer process comprising at least the steps of:
reading data obtained from the synchronized electrocardiogram tomographic imaging corresponding to 3dimensional images at different time bins, said images being defined by pixels;
determining from data obtained from the synchronized electrocardiogram tomographic imaging a reference position of a first portion of the heart selected from the group consisting of the valvular plane, at least a portion of the septum and the valvular plane with at least a portion of the septum;
determining from said data obtained from the synchronized electrocardiogram tomographic imaging a position of the the first portion of the heart at each time bin;
for each time bin, determining a movement for matching the first portion at the considered time bin with the reference position of the first portion;
using the determined movement for correcting the 3dimensional images at the different time bins, and
using the corrected 3dimensional images for determining an accurate localisation an of the heart.
Said second object of the invention is advantageously implemented in the first object of the invention, but can be implemented in any other existing treatment of data obtained from synchronized electrocardiogram tomoscintigraphy or from electrocardiogram tomographic imaging.
In said second object, the computer process comprises advantageously the steps of:
determining from data obtained from the synchronized electrocardiogram tomographic imaging a reference position of the valvular plane;
determining from said data obtained from the synchronized electrocardiogram tomographic imaging a position of the valvular plane at each time bin, and
for each time bin, determining a movement for matching the valvular plane at the considered time bin with the reference position of the valvular plane.
In an embodiment of said second object, the computer process comprises advantageously the steps of:
determining from data obtained from the synchronized electrocardiogram tomographic imaging a reference position of the valvular plane and at least a portion of the septum;
determining from said data obtained from the synchronized electrocardiogram tomographic imaging a position of the valvular plane and at least a portion of the septum at each time bin, and
for each time bin, determining a movement for matching the valvular plane and at least a portion of the septum at the considered time bin with the reference position of the valvular plane and septum.
In another embodiment of said second object, the computer process comprises advantageously the steps of:
determining from data obtained from the synchronized electrocardiogram tomographic imaging a reference position of at least a portion of the septum;
determining from said data obtained from the synchronized electrocardiogram tomographic imaging a position of at least a portion of the septum at each time bin, and
for each time bin, determining a movement for matching at least a portion of the septum at the considered time bin with the reference position of at least a portion of the septum.
A third object of the invention is a computer program storage medium readable by a computing system and encoding a computer program of instructions for executing a computer process for the treatment of data obtained from synchronized electrocardiogram tomographic imaging, especially electrocardiogram tomoscintigraphy, said data being correlated to image giving the activity of a heart comprising auricles, ventricles, valves and septum, said image comprising at least: (a) a first portion consisting of the pixels showing the auricles and ventricles during the cardiac cycle, each cycle comprising successive time bins with an end-systole time and end-diastole time, and (b) a second portion consisting of pixels substantially not involved with said cardiac activity, said computer process comprising at least the steps of:
reading data obtained from the synchronized electrocardiogram tomographic imaging corresponding to 3dimensional images at different time bins, said images being defined by pixels;
determining from data obtained from the synchronized electrocardiogram tomographic imaging a position of a portion of the heart selected from the group consisting of the valvular plane, at least a portion of the septum and the valvular plane with at least a portion of the septum;
labeling in the image from said position at least a region of interest selected from the group consisting of left ventricle, right ventricle, left auricle, right auricle, ventricles, auricles, left auricle and left ventricle, right auricle and right ventricle.
Said third object of the invention, with possibly its details or characteristics of possible embodiments thereof, is advantageously implemented in the first and/or second object of the invention, but can be implemented in any other existing treatment of data obtained from synchronized electrocardiogram tomoscintigraphy or from electrocardiogram tomographic imaging.
According to an embodiment of the third object of the invention, said computer process comprises at least the steps of:
reading data obtained from the synchronized electrocardiogram tomographic imaging corresponding to 3dimensional images at different time bins, said images being defined by pixels;
determining from data obtained from the synchronized electrocardiogram tomographic imaging, at each time bin, a position of a portion of the heart selected from the group consisting of the valvular plane, at least a portion of the septum and the valvular plane with at least a portion of the septum;
labeling in the image at each time bin, from said position at least a region of interest selected from the group consisting of left ventricle, right ventricle, left auricle, right auricle, ventricles, auricles, left auricle and left ventricle, right auricle and right ventricle.
According to another embodiment of the third object of the invention, said computer process comprises at least the steps of:
determining from data obtained from the synchronized electrocardiogram tomographic imaging, a position of the valvular plane with at least a portion of the septum;
labeling in the image, at least a region of interest selected from the group consisting of left ventricle, right ventricle, left auricle, right auricle.
According to a detail of the third object of the invention, said computer process comprises at least the steps of:
determining from data obtained from the synchronized electrocardiogram tomographic imaging a position of the valvular plane with at least a portion of the septum;
labeling in the image, from said position, at least two regions of interest selected from the group consisting of left ventricle, right ventricle, left auricle, right auricle.
According to another detail of the third object of the invention, said computer process comprises at least the steps of:
determining from data obtained from the synchronized electrocardiogram tomographic imaging a reference position of a first portion of the heart selected from the group consisting of the valvular plane, at least a portion of the septum and the valvular plane with at least a portion of the septum;
determining from said data obtained from the synchronized electrocardiogram tomographic imaging a position of the the first portion of the heart at each time bin;
for each time bin, determining a movement for matching the first portion at the considered time bin with the reference position of the first portion;
using the determined movement for correcting the 3dimensional images at the different time bins, and
using the corrected 3dimensional images for determining an accurate localisation of the heart.
According to still another embodiment of the third object of the invention, said computer process comprises at least the steps of:
determining from data obtained from the synchronized electrocardiogram tomographic imaging a reference position of the valvular plane
determining from said data obtained from the synchronized electrocardiogram tomographic imaging a position of the valvular plane at each time bin, and
for each time bin, determining a movement for matching the valvular plane at the considered time bin with the reference position of the valvular plane.
According to a possible characteristic of the third object of the invention, said computer process comprises at least the steps of:
determining from data obtained from the synchronized electrocardiogram tomographic imaging a reference position of the valvular plane and at least a portion of the septum;
determining from said data obtained from the synchronized electrocardiogram tomographic imaging a position of the valvular plane and at least a portion of the septum at each time bin, and
for each time bin, determining a movement for matching the valvular plane and at least a portion of the septum at the considered time bin with the reference position of the valvular plane and septum.
According to still another possible characteristic of the third object of the invention, said computer process comprises at least the steps of:
determining from data obtained from the synchronized electrocardiogram tomoscintigraphy a reference position of the septum;
determining from said data obtained from the synchronized electrocardiogram tomoscintigraphy a position of the septum at each time bin, and
for each time bin, determining a movement for matching the septum at the considered time bin with the reference position of the septum.
A fourth object of the invention is a computer program storage medium readable by a computing system and encoding a computer program of instructions for executing a computer process for the treatment of data obtained from synchronized electrocardiogram tomoscintigraphy, said data being correlated to image giving the activity of a heart comprising auricles, ventricles, valves and septum, said image comprising at least: (a) a first portion consisting of the pixels showing the auricles and ventricles during the cardiac cycle, each cycle comprising successive time bins with an end-systole time and end-diastole time, and (b) a second portion consisting of pixels substantially not involved with said cardiac activity, said computer process comprising at least the steps of:
reading data obtained from the synchronized electrocardiogram tomoscintigraphy corresponding to 3dimensional images at different time bins, said images being defined by pixels;
determining and labeling from data obtained from the synchronized electrocardiogram tomoscintigraphy at least a segment corresponding to at least a part of an organ selected from the group consisting of aorta descendens, spleen, liver, valvular plane, the septum, ventricle, auricle.
Said fourth object of the invention, with possibly its details or characteristics of possible embodiments thereof, is advantageously implemented in the first and/or second and/or third object of the invention, but can be implemented in any other existing treatment of data obtained from synchronized electrocardiogram tomoscintigraphy.
In said fourth object, the computer process comprises advantageously the steps of:
labeling in the image a region corresponding to the Aorta descendens;
labeling in the image a region corresponding to the spleen;
labelling in the image a region corresponding to the valvular plane and a region correponding to the septum;
from said labeled regions of the valvular plane and septum, determining and labeling in the image regions corresponding to the ventricles and the auricles.
A fifth object of the invention is a computer program storage medium readable by a computing system and encoding a computer program of instructions for executing a computer process for the treatment of data obtained from synchronized electrocardiogram tomoscintigraphy, said data being correlated to image giving the activity of a heart comprising auricles, ventricles, valves and septum, said image comprising at least: (a) a first portion consisting of the pixels showing the auricles and ventricles during the cardiac cycle, each cycle comprising successive time bins with an end-systole time and end-diastole time, and (b) a second portion consisting of pixels substantially not involved with said cardiac activity, said computer process comprising at least the steps of:
reading data obtained from the synchronized electrocardiogram tomoscintigraphy corresponding to 3dimensional images at different time bins, said images being defined by pixels;
determining pixels defining at least a part of a wall of a region of interest of the heart;
determining for said part an average activity at each time bin,
determining for said part for at least a part of the heart cycle, an average slope of activity in function of time bins;
determining for each pixel of the part considered and for the portion of heart cycle considered, an actual slope of activity in function of time bins, and
determining a status parameter of pixels defining the part considered, by comparison for the pixel considered, the actual slope of activity with the average slope.
Said fifth object of the invention, with possibly its details or characteristics of possible embodiments thereof, is advantageously implemented in the first and/or second and/or third and/or fourth object of the invention, but can be implemented in any other existing treatment of data obtained from synchronized electrocardiogram tomoscintigraphy.
A sixth object of the invention is a computer program storage medium readable by a computing system and encoding a computer program of instructions for executing a computer process for the treatment of data obtained from synchronized electrocardiogram tomoscintigraphy, said data being correlated to image giving the activity of a heart comprising auricles, ventricles, valves and septum, said image comprising at least: (a) a first portion consisting of the pixels showing the auricles and ventricles during the cardiac cycle, each cycle comprising successive time bins with an end-systole time and end-diastole time, and (b) a second portion consisting of pixels substantially not involved with said cardiac activity, said computer process comprising at least the steps of:
reading data obtained from the synchronized electrocardiogram tomoscintigraphy corresponding to 3dimensional images at different time bins, said images being defined by pixels;
determining pixels defining at least a part of a wall of a region of interest of the heart;
determining for said part an average activity at each time bin,
determining for said part for at least a part of the heart cycle, an average slope of activity in function of time bins;
determining a correlation, time bin per time bin, for the pixels of the part considered, between the actual activity and the average activity of the part considered, and
determining, from the correlation, a status parameter of pixels defining the part considered.
Advantageously, the computer process determines a correlation, during the heart cycle, for the pixels of the part considered, between the actual activity and the average activity of the part considered.
Said sixth object of the invention, with possibly its details or characteristics of possible embodiments thereof, is advantageously implemented in the first and/or second and/or third and/or fourth and/or fifth object of the invention, but can be implemented in any other existing treatment of data obtained from synchronized electrocardiogram tomoscintigraphy.
A seventh object of the invention is a computer program storage medium readable by a computing system and encoding a computer program of instructions for executing a computer process for the treatment of data obtained from synchronized electrocardiogram tomoscintigraphy, said data being correlated to image giving the activity of a heart comprising auricles, ventricles, valves and septum, said image comprising at least: (a) a first portion consisting of the pixels showing the auricles and ventricles during the cardiac cycle, each cycle comprising successive time bins with an end-systole time and end-diastole time, and (b) a second portion consisting of pixels substantially not involved with said cardiac activity, said computer process comprising at least the steps of:
reading data obtained from the synchronized electrocardiogram tomoscintigraphy corresponding to 3dimensional images at different time bins, said images being defined by pixels;
determining pixels defining at least a part of the peel of the right ventricles, said ventricle having the general shape of a tube with a point of cuvature extending between two valves;
determining a 3dimensional parameter for the pixels considered;
using a transform for showing said 3 dimensional parameter in a 2dimensional representation, said transform defining the 3D position of each considered pixel by a first parameter following the tube from a first valve up to the other valve and defining the position of the pixel correlated to a distance between the pixel considered and the first valve following the tube, and a second parameter correlated to the position of the pixel in a plane passing through the pixel considered.
Said seventh object of the invention, with possibly its details or characteristics of possible embodiments thereof, is advantageously implemented in the first and/or second and/or third and/or fourth and/or fifth and/or sixth object of the invention, but can be implemented in any other existing treatment of data obtained from synchronized electrocardiogram tomoscintigraphy.
In the seventh object of the invention, the transform defines advantageously each pixel by parameters characterizing the position of the pixel considered in a plane passing through said pixel and through a base defined between the first and second valves.
Preferably, the position of each pixel of the peel of the right ventricle is defined by the parameters i and j, said parameter being determined by the following formulas:
xcex8=arc tangent((ybasexe2x88x92y)/(zxe2x88x92zcog))
i=NSA*(xcex8xe2x88x92xcex80)/(xcex8exe2x88x92xcex80)
r=sqrt((ybasexe2x88x92y)2+(zxe2x88x92zcog)2)
j=(NPSA/2xcfx80)*arc tangent ((xxe2x88x92xcog,i)/(rxe2x88x92rcog,i)
whereby
x,y,z are the position of the pixel considered along three perpendicular axis;
ybase is the y position of the base;
xcex80, xcex8e are the start- and stop angle over which i rotates (for example 18xc2x0 and 150xc2x0);
zcog is the global center of gravity of the RV;
xcog,i, rcog,i are respectively the x and r positions of the center of gravity of the RV in the i-plane;
NSA is the number of concentric circles in the bullseye;
NPSA is the number of sectors in the bullseye.
A eight object of the invention is a computer program storage medium readable by a computing system and encoding a computer program of instructions for executing a computer process for the treatment of data obtained from synchronized electrocardiogram tomoscintigraphy, said data being correlated to image giving the activity of a heart comprising auricles, ventricles, valves and septum, said image comprising at least: (a) a first portion consisting of the pixels showing the auricles and ventricles during the cardiac cycle, each cycle comprising successive time bins with an end-systole time and end-diastole time, and (b) a second portion consisting of pixels substantially not involved with said cardiac activity, said computer process comprising at least the steps of:
reading data obtained from the synchronized electrocardiogram tomoscintigraphy corresponding to 3dimensional images at different time bins, said images being defined by pixels;
determining pixels defining at least a part of a wall of the right ventricle, said ventricle having the general shape of a tube with a point of cuvature extending between two valves;
determining for said part an average activity at each time bin,
determining for said part for at least a part of the heart cycle, an average slope of activity in function of time bins;
determining for each pixel of the part considered and for the portion of heart cycle considered, an actual slope of activity in function of time bins, and
determining a status parameter of pixels defining the part considered, by comparison for the pixel considered, the actual slope of activity with the average slope;
determining a 3dimensional parameter for the pixels considered and using a transform for showing said 3 dimensional parameter in a 2dimensional representation, said transform defining the 3D position of each considered pixel by a first parameter following the tube from a first valve up to the other valve and defining the position of the pixel correlated to a distance between the pixel considered and the first valve following the tube, and a second parameter correlated to the position of the pixel in a plane passing through the pixel considered, and
representing the status parameter of the pixel in said two dimensional representation.
Advantageously, the transform defines each pixel by parameters characterizing the position of the pixel considered in a plane passing through said pixel and through a base defined between the first and second valves.
Preferably, the position of each pixel of the peel of the right ventricle is defined by the parameters i and j, said parameter being determined by the following formulas:
xcex8=arc tangent((ybasexe2x88x92y)/(zxe2x88x92zcog))
i=NSA*(xcex8xe2x88x92xcex80)/(xcex8exe2x88x92xcex80)
r=sqrt((ybasexe2x88x92y)2+(zxe2x88x92zcog )2)
j=(NPSA/2xcfx80)*arc tangent ((xxe2x88x92xcog,i)/(rxe2x88x92rcog,i)
whereby
x,y,z are the position of the pixel considered along three perpendicular axis;
ybase is the y position of the base;
xcex80, xcex8e are the start- and stop angle over which i rotates (for example 18xc2x0 and 150xc2x0);
zcog is the global center of gravity of the RV;
xcog,i, rcog,i are respectively the x and r positions of the center of gravity of the RV in the i-plane;
NSA is the number of concentric circles in the bullseye;
NPSA is the number of sectors in the bullseye.
Said eigth object of the invention, with possibly its details or characteristics of possible embodiments thereof, is advantageously implemented in the first and/or second and/or third and/or fourth and/or fifth and/or sixth and/or seventh object of the invention, but can be implemented in any other existing treatment of data obtained from synchronized electrocardiogram tomoscintigraphy.
A ninth object of the invention is a computer program storage medium readable by a computing system and encoding a computer program of instructions for executing a computer process for the treatment of data obtained from synchronized electrocardiogram tomoscintigraphy, said data being correlated to image giving the activity of a heart comprising auricles, ventricles, valves and septum, said image comprising at least: (a) a first portion consisting of the pixels showing the auricles and ventricles during the cardiac cycle, each cycle comprising successive time bins with an end-systole time and end-diastole time, and (b) a second portion consisting of pixels substantially not involved with said cardiac activity, said computer process comprising at least the steps of:
reading data obtained from the synchronized electrocardiogram tomoscintigraphy corresponding to 3dimensional images at different time bins, said images being defined by pixels;
determining pixels defining at least a part of a wall of a region of interest of the heart;
determining for said part an average activity at each time bin,
determining for said part for at least a part of the heart cycle, an average slope of activity in function of time bins;
determining a correlation, time bin per time bin, for the pixels of the part considered, between the actual activity and the average activity of the part considered, and
determining, from the correlation, a status parameter of pixels defining the part considered, by comparison for the pixel considered, the actual slope of activity with the average slope;
determining a 3dimensional parameter for the pixels considered and using a transform for showing said 3 dimensional parameter in a 2dimensional representation, said transform defining the 3D position of each considered pixel by a first parameter following the tube from a first valve up to the other valve and defining the position of the pixel correlated to a distance between the pixel considered and the first valve following the tube, and a second parameter correlated to the position of the pixel in a plane passing through the pixel considered, and
representing the status parameter of the pixel in said two dimensional representation.
Advantageously, the transform defines each pixel by parameters characterizing the position of the pixel considered in a plane passing through said pixel and through a base defined between the first and second valves.
Preferably, the position of each pixel of the peel of the right ventricle is defined by the parameters i and j, said parameter being determined by the following formulas:
xcex8=arc tangent((ybasexe2x88x92y)/(zxe2x88x92zcog))
i=NSA*(xcex8xe2x88x92xcex80)/(xcex8cxe2x88x92xcex80)
r=sqrt((ybasexe2x88x92y)2+(zxe2x88x92zcog)2)
j=(NPSA/2xcfx80)*arc tangent ((xxe2x88x92xcog,i)/(rxe2x88x92rcog,i)
whereby
x,y,z are the position of the pixel considered along three perpendicular axis;
ybase is the y position of the base;
xcex80, xcex8e are the start- and stop angle over which i rotates (for example 18xc2x0 and 150xc2x0);
zcog is the global center of gravity of the RV;
xcog,i, rcog,i are respectively the x and r positions of the center of gravity of the RV in the i-plane;
NSA is the number of concentric circles in the bullseye;
NPSA is the number of sectors in the bullseye.
Most preferably, the computer process determines a correlation, during the heart cycle, for the pixels of the part considered, between the actual activity and the average activity of the part considered.
Said ninth object of the invention, with possibly its details or characteristics of possible embodiments thereof, is advantageously implemented in the first and/or second and/or third and/or fourth and/or fifth and/or sixth and/or seventh and/or eigth object of the invention, but can be implemented in any other existing treatment of data obtained from synchronized electrocardiogram tomoscintigraphy.
A tenth object of the invention is a computer program storage medium readable by a computing system and encoding a computer program of instructions for executing a computer process for the treatment of data obtained from synchronized electrocardiogram tomographic imaging, especially electrocardiogram tomoscintigraphy, said data being correlated to image giving the activity of a heart comprising auricles, ventricles, valves and septum, said image comprising at least: (a) a first portion consisting of the pixels showing the auricles and ventricles during the cardiac cycle, each cycle comprising successive time bins with an end-systole time and end-diastole time, and (b) a second portion consisting of pixels substantially not involved with said cardiac activity, said computer process comprising at least the steps of:
reading data obtained from the synchronized electrocardiogram tomoscintigraphy corresponding to 3dimensional images at different time bins, said images being defined by pixels;
using a matched filter for determining a parameter of pixels in function of a non spatial dimension.
Advantageously, the computer process comprises the steps of:
determining pixels defining at least a part of a wall of a region of interest of the heart;
determining for said part, by using a matched filter, an average activity at each time bin,
determining for said part for at least a part of the heart cycle, by using a matched filter, an average slope of activity in function of time bins;
determining for each pixel of the part considered and for the portion of heart cycle considered, an actual slope of activity in function of time bins, and
determining a status parameter of pixels defining the part considered, by comparison for the pixel considered, the actual slope of activity with the average slope.
According to a possible embodiment, the computer process comprises the step of:
determining for said part an average activity at each time bin, by using a matched filter,
determining, by using a matched filter, for said part for at least a part of the heart cycle, an average slope of activity in function of time bins;
determining a correlation, time bin per time bin, for the pixels of the part considered, between the actual activity and the average activity of the part considered, and
determining, from the correlation, a status parameter of pixels defining the part considered.
Preferably in said embodiment, the computer process further comprises the steps of:
determining pixels defining at least a part of a wall of the right ventricle;
determining a 3dimensional parameter for the pixels considered and using a transform for showing said 3 dimensional parameter in a 2dimensional representation, said transform defining the 3D position of each considered pixel by a first parameter following the tube from a first valve up to the other valve and defining the position of the pixel correlated to a distance between the pixel considered and the first valve following the tube, and a second parameter correlated to the position of the pixel in a plane passing through the pixel considered, and
representing the status parameter of the pixel in said two dimensional representation.
According to another possible embodiment of the tenth object of the invention, the computer process further comprises the steps of:
a determining pixels defining at least a part of a wall of the right ventricle;
determining a 3dimensional parameter for the pixels considered and using a transform for showing said 3 dimensional parameter in a 2dimensional representation, said transform defining the 3D position of each considered pixel by a first parameter following the tube from a first valve up to the other valve and defining the position of the pixel correlated to a distance between the pixel considered and the first valve following the tube, and a second parameter correlated to the position of the pixel in a plane passing through the pixel considered, and
representing the status parameter of the pixel in said two dimensional representation.
Said tenth object of the invention, with possibly its details or characteristics of possible embodiments thereof, is advantageously implemented in the first and/or second and/or third and/or fourth and/or fifth and/or sixth and/or seventh and/or eigth and/or ninth object of the invention, but can be implemented in any other existing treatment of data obtained from synchronized electrocardiogram tomoscintigraphy or from electrocardiogram tomographic imaging. A 11th object of the invention is a computer program storage medium readable by computing system and encoding a computer program of instructions for executing computer process for the treatment of data obtained from synchronized electrocardiogram tomoscintigraphy, said data being correlated to image giving the activity of a heart comprising auricles, ventricles, valves and septum, said image comprising at least: (a) a first portion consisting of the pixels showing the auricles and ventricles during the cardiac cycle, each cycle comprising successive time bins with an end-systole time and end-diastole time, and (b) a second portion consisting of pixels substantially not involved with said cardiac activity, said computer process comprising at least the steps of:
reading data from the electrocardiogram tomoscintigraphy giving images of the activity pixel at each time bin;
determining from said images a variation parameter for pixels over the time;
determining at least from said variation parameter at least two segments selected from the group consisting of the ventricular segments and the auricular segments;
determining from said at least two segments, a segment selected from the group consisting of the valvular plane and the septum.
Advantageously, the computer process comprises the step of:
determining the ventricular segments and the auricular segments, and
determining the valvular plane between said segments.
Preferably, a segmentation of pixels is operated in function of the determined parameter variation so as to define various segments, in which the segments are merged upto a limited number of segments, while a labeling of the segments is operated as being a label selected from the group consisting of ventricular, auricular, right and left.
According to a possible embodiment, the ventricle segments and the auricle segments are labeled by at least two different methods, and in which the computer process comprises a voting instruction for labeling the segments as being ventricle or auricle.
According top another possible embodiment, the computer process further comprises the steps of:
determining for pixels corresponding to ventricles and auricles, the maximum activity over time;
segmenting the pixels in function of their maximum activity, so as to define segments separated by valley,
merging segments with a low valley therebetween up to obtain less than 8 merged segments;
determining at least from said merged segments a ventricle segment and an auricle segment, and
labeling the region between the left and right sides as the valvular plane.
According to particularities of embodiments,
the computer process labels the left side and right side segments by at least two different methods, and in which the computer process comprises a voting instruction for labeling the segments as being left or right, or
the computer process further comprises the steps of:
determining for pixels corresponding to the left and right side segments, the maximum activity over time;
segmenting the pixels in function of their maximum activity, so as to define segments separated by valley,
merging segments with a low valley therebetween up to obtain less than 8 merged segments;
determining at least from said merged segments a left side and a right side of the heart, and
labeling the region between the left and right sides as the septum.
According to a further embodiment, the computer process further comprises the steps of:
determining for pixels corresponding to ventricles and auricles, the maximum variation of activity over time;
segmenting the pixels in function of their maximum variation of activity, so as to define segments separated by valley,
merging segments with a low valley therebetween up to obtain less than 8 merged segments;
determining at least from said merged segments a ventricle segment and an auricle segment, and
labeling the region between the left and right sides as the valvular plane.
Said 11th object of the invention, with possibly its details or characteristics of possible embodiments thereof, is advantageously implemented in the first and/or second and/or third and/or fourth and/or fifth and/or sixth and/or seventh and/or eigth and/or ninth and/or tenth object of the invention, but can be implemented in any other existing treatment of data obtained from synchronized electrocardiogram tomoscintigraphy.
According to possible embodiments of the 1st to 11th inventions, the ROI (region of interest) considered is manually labelled and/or segmented.
The invention relates also to methods corresponding to the processing steps of one of the computer programs of a storage medium of the invention, as well as to an apparatus comprising means for executing the computer program and/or the method according to one of the object of the invention.
Said apparatus is an apparatus for executing in a computing system the treatment of data obtained from synchronized electrocardiogram tomoscintigraphy or from a electrocardiogram tomographic imaging, said data being correlated to image giving the activity of a heart comprising auricles, ventricles, valves and septum, said image comprising at least: (a) a first portion consisting of the pixels showing the auricles and ventricles during the cardiac cycle, each cycle comprising successive time bins with an end-systole time and end-diastole time, and (b) a second portion consisting of pixels substantially not involved with said cardiac activity, said apparatus comprising a processor, an input/output device, and a data storage device, said apparatus comprising at least means for executing the computer process according to any one of the inventions, and more particularly one or more of the followings means:
means for reading data obtained from the synchronized electrocardiogram tomoscintigraphy or from from a electrocardiogram tomographic imaging, said data corresponding to 3dimensional images at different time bins, said images being defined by pixels;
means for determining for at least a part of the second portion of the image an activity for at least a part of a cardiac activity cycle period;
means for normalizing the activity at each time bin in function of said determined activity for said part of the second portion of the image;
means for determining a rigid model comprising a reference valvular plane and a reference septum;
means for determining for each time bin, the valvular plane and the septum;
means for determining, for each time bin, the correction movement for matching the valvular plane and the septum at the considered time bin with the rigid model;
means using the correction movement for correcting the activity of the pixel at each time bin;
means for determining the time bins for the end-systole and the end-diastole;
means for determining the phase and amplitude of pixels of the 3dimensional images;
means for segmenting the images in region of interest selected in the group consisting of ventricles and auricles;
means for temporal and spatial filtering;
means for labeling the ventricles and the auricles
means for computing at least a parameter selected from the group consisting of activity curves, thickness of the septum, ventricular movements;
means for determining of 2D representations of activity curves, and
means for displaying results
or one or means executing several processing steps of one or more of the programs of the invention (1 to 11th objects of the invention).
The invention has still for object an apparatus for synchronized electrocardiogram tomoscintigraphy or for electrocardiogram tomographic imaging, said apparatus comprising a computing system for executing the treatment of data obtained from synchronized electrocardiogram tomoscintigraphy or from a electrocardiogram tomographic imaging, said data being correlated to image giving the activity of a heart comprising auricles, ventricles, valves and septum, said image comprising at least: (a) a first portion consisting of the pixels showing the auricles and ventricles during the cardiac cycle, each cycle comprising successive time bins with an end-systole time and end-diastole time, and (b) a second portion consisting of pixels substantially not involved with said cardiac activity, said apparatus comprising a processor, an input/output device, and a data storage device, said computing system comprising at least means for executing one or more of the programs of the invention and/or one or more methods according to the invention, said apparatus comprising one or more of the following means:
means for reading data obtained from the synchronized electrocardiogram tomoscintigraphy or from a electrocardiogram tomographic imaging, said data corresponding to 3dimensional images at different time bins, said images being defined by pixels;
means for determining for at least a part of the second portion of the image an activity for at least a part of a cardiac activity cycle period;
means for normalizing the activity at each time bin in function of said determined activity for said part of the second portion of the image;
means for determining a rigid model comprising a reference valvular plane and a reference septum;
means for determining for each time bin, the valvular plane and the septum;
means for determining, for each time bin, the correction movement for matching the valvular plane and the septum at the considered time bin with the rigid model;
means using the correction movement for correcting the activity of the pixel at each time bin;
means for determining the time bins for the end-systole and the end-diastole;
means for determining the phase and amplitude of pixels of the 3dimensional images;
means for segmenting the images in region of interest selected in the group consisting of ventricles and auricles;
means for temporal and spatial filtering;
means for labeling the ventricles and the auricles
means for computing at least a parameter selected from the group consisting of activity curves, thickness of the septum, ventricular movements;
means for determining of 2D representations of activity curves, and
means for displaying results
or one or means executing several processing steps of one or more of the programs of the invention (1 to 11th objects of the invention).